Improving coherent population transfer via a stricter adiabatic condition

High-fidelity fast and robust coherent population transfer is a major challenge in coherent quantum control. At present, all coherent population transfer approaches are based on a well-known adiabatic condition. In this work, we demonstrate that a more strict adiabatic condition can markedly improve the performance of the coherent population transfer approach. Based on this, we propose a coherent population transfer approach, which just needs only one control parameter and depends on the eigenvalues of the systems. Comparing to other approaches, we numerically demonstrate that our approach can provide a more robustness coherent population transfer without affecting the fidelity and speed. Moreover, this approach may be generalized to complex quantum systems where the exact expressions of eigenstates are difficult to obtain or the parameters of systems are difficult to simultaneously drive. In short, our idea provides a way to further improve the performance of coherent population transfer approaches.